The invention relates to a shuttle monitoring device, particularly for multi-shuttle weaving machines with positively driven shuttles provided with magnets.
The invention is particularly applicable to multi-shuttle weaving machines having shuttles provided with permanent magnets of alternating polarity arranged in succession, with a multi-pole magnetic guide field being moved along the warp surface and causing the shuttle with its permanent magnets to be carried along its proper path, the guide field being established by corresponding magnets of alternating polarity arranged in succession.
With weaving machines it is advantageous to monitor the travel of the shuttles which serve as the weft yarn inserting means, during the weft yarn insertion operation, in order to immediately shut down the weaving machine upon the detection of irregularities in shuttle movement, before a weft yarn break or other malfunction or even damage to the fabric being woven or to the weaving machine itself can occur.
In the case of shuttles which are thrown through the shed, i.e., in contrast to those which are positively transported through the entire length of the shed, it is already known to monitor the velocity of the shuttle upon the insertion of a weft yarn, in order to be able to derive indications of malfunction from velocity deviations. In that case, the shuttles are provided with permanent magnets which move past an inductive transducer. Such a shuttle monitoring device is not suited for weaving machines, especially multi-shuttle weaving machines, in which the shuttles are positively transported through the entirety of the shed and are not merely thrown through.